Cylindrical containers are described in the following patents as being “leak-proof.” For example, cylindrical leak-proof containers are disclosed in U.S. Pat. Nos. 4,783,056, 4,812,116, RE 37,676 and U.S. Pat. No. 6,303,064. The disclosure of the processes of producing injection molded plastic containers and sealing them are incorporated by reference herein.
Co-pending U.S. application Ser. No. 09/386,702, filed Aug. 31, 1999, now U.S. Pat. No. 6,769,558, issued Aug. 3, 2004, and assigned to the same assignee as the present application, discloses a leakproof, resealable cylindrical container and cap assembly, which comprises a cap and container attached by a hinge. The cylindrical container has an upper portion and an outer surface, and at the upper portion, the container has a rim. The cap has a circular base portion with an outer periphery and a cylindrical tubular skirt extending perpendicularly and outwardly around said outer periphery of the base; the skirt has an inner wall, which includes at least one recess. The cylindrical cap and container assembly, when in the closed position, form a leakproof, air tight seal. The cap and container may be integrally molded of plastic, forming a hinge there between.